The Australian Transport Safety Bureau (ATSB) is Australia's national transport safety investigator. The ATSB's function is to improve safety and public confidence in the aviation, marine and rail modes of transport. The ATSB is Australia's prime agency for the independent investigation of civil aviation, rail and maritime accidents, incidents and safety deficiencies.

The ATSB has commenced an investigation into a signal passed at danger (SPAD) rail occurrence, that occurred near Bowen Hills station in Brisbane, Queensland.

At about 0948 on 26 August 2017, a suburban passenger train, designation 1A21, exceeded its limit of authority by passing signal ME45 at danger. The train came to a stop about 40 m on the departure side of the signal. The signal had been placed at stop to define the limit of a Track Occupancy Authority, where workers were accessing the danger zone to walk across a portion of track to undertake work.